Lubricating oil compositions containing pre-ceramic polymers

Abstract

A lubricating composition comprises an oil of lubricating viscosity, a metal-free pre-ceramic polymer and one or more co-additives. The metal-free pre-ceramic polymer comprises a plurality of repeat units which do not contain oxygen. The pre-ceramic polymers provide the lubricating oil composition with antiwear properties. Also described is a method of lubricating an internal combustion engine and the use of a lubricating oil composition containing a pre-ceramic polymers to inhibit wear in an internal combustion engine.

What is claimed is: 
     
       1. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; 
         or wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms, wherein said metal-free pre-ceramic polymer having a repeat unit of formula (I): is not capped with an amine or polyamine. 
       
     
     
       2. A lubricating oil composition according to  claim 1  wherein the metal-free pre-ceramic polymer is capped at one or both ends by a capping or chain-terminating group. 
     
     
       3. A lubricating oil composition according to  claim 1  wherein the number of repeat units of formulae (I) to (IV) in the metal-free pre-ceramic polymer is in the range from 2 to 100. 
     
     
       4. A lubricating oil composition according to  claim 1  wherein at least one of R, R 1 , R 2 , R 3 , R 5 , R 6  and R 7  contains at least 3 carbon atoms, and/or any capping or chain-terminating group contains such a group. 
     
     
       5. A lubricating oil composition according to  claim 1  wherein the metal-free pre-ceramic polymer is present in the lubricating oil composition in an amount of between 0.001 and 10 percent by weight, based on the weight of the composition. 
     
     
       6. A lubricating oil composition according to  claim 1  wherein the one or more co-additives comprises an antiwear additive, an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant. 
     
     
       7. A lubricating oil composition according to  claim 6  which does not contain a zinc dihydrocarbyl dithiophosphate. 
     
     
       8. A method of lubricating a spark-ignited or compression-ignited internal combustion engine, the method comprising lubricating the engine with a lubricating oil composition according to  claim 1 . 
     
     
       9. A lubricating oil composition of  claim 1 , wherein said metal-free pre-ceramic polymer is capped at one or both ends by a capping or chain-terminating group selected from the group consisting of an amide group, an ester, an ether, and a thioether. 
     
     
       10. A lubricating oil composition of  claim 1 , wherein said metal-free pre-ceramic polymer is capped at one or both ends by an amide group. 
     
     
       11. A lubricating oil composition of  claim 10 , wherein the number of repeat units of formulae (I) to (IV) in the metal-free pre-ceramic polymer from is from 2 to 5. 
     
     
       12. A lubricating oil composition of  claim 10 , wherein at least one of R, R 1 , R 2 , R 3 , R 5 , R 6  and R 7  contain at least 12 carbon atoms. 
     
     
       13. A lubricating oil composition of  claim 10 , wherein at least one of R 1  and R 2  contains at least 12 carbon atoms. 
     
     
       14. A method of lubricating a spark-ignited or compression-ignited internal combustion engine comprising lubricating the engine with the lubricating oil composition of  claim 10 . 
     
     
       15. A lubricating oil composition of  claim 1 , wherein the number of repeat units of formulae (I) to (IV) in the metal-free pre-ceramic polymer is from 2 to 100. 
     
     
       16. A lubricating oil composition of  claim 1 , wherein the number of repeat units of formulae (I) to (IV) in the metal-free pre-ceramic polymer from is from 2 to 5. 
     
     
       17. A lubricating oil composition of  claim 1 , wherein at least one of R, R 1 , R 2 , R 3 , R 5 , R 6  and R 7  contain at least 8 carbon atoms. 
     
     
       18. A lubricating oil composition of  claim 1 , wherein R contains at least 8 carbon atoms. 
     
     
       19. A lubricating oil composition of  claim 1 , wherein R contains at least 12 carbon atoms. 
     
     
       20. A lubricating oil composition of  claim 1 , wherein at least one of R 1  and R 2  contains at least 8 carbon atoms. 
     
     
       21. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; 
         or wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms, wherein the repeat units of formulae (I) to (VI) form a closed ring structure. 
       
     
     
       22. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer comprises a compound of structure (VII): 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2  and R 8  are independently hydrocarbyl groups containing 1 to 30 carbon atoms, provided that at least one of R 1 , R 2  and R 8  contains at least 3. 
       
     
     
       23. A lubricating oil composition according to  claim 22  wherein the metal-free pre-ceramic polymer is present in the lubricating oil composition in an amount of between 0.001 and 10 percent by weight, based on the weight of the composition. 
     
     
       24. A lubricating oil composition according to  claim 22  wherein the one or more co-additives comprises an antiwear additive, an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant. 
     
     
       25. A lubricating oil composition according to  claim 24  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide from greater than 800 ppm to 1200 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       26. A lubricating oil composition according to  claim 24  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide no greater than 800 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       27. A lubricating oil composition according to  claim 22  which does not contain a zinc dihydrocarbyl dithiophosphate. 
     
     
       28. A method of lubricating a spark-ignited or compression-ignited internal combustion engine, the method comprising lubricating the engine with a lubricating oil composition according to  claim 22 . 
     
     
       29. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer comprises a compound of structure (VIII): 
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are independently hydrocarbyl groups containing 1 to 30 carbon atoms, provided that at least one of R 1  and R 2  contains at least 3 carbon atoms. 
     
     
       30. A lubricating oil composition according to  claim 29  wherein the metal-free pre-ceramic polymer is present in the lubricating oil composition in an amount of between 0.001 and 10 percent by weight, based on the weight of the composition. 
     
     
       31. A lubricating oil composition according to  claim 29  wherein the one or more co-additives comprises an antiwear additive, an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant. 
     
     
       32. A lubricating oil composition according to  claim 31  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide from greater than 800 ppm to 1200 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       33. A lubricating oil composition according to  claim 31  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide no greater than 800 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       34. A lubricating oil composition according to  claim 29  which does not contain a zinc dihydrocarbyl dithiophosphate. 
     
     
       35. A method of lubricating a spark-ignited or compression-ignited internal combustion engine, the method comprising lubricating the engine with a lubricating oil composition according to  claim 29 . 
     
     
       36. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer comprises a mixture of a compound of structure (VII): 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2  and R 8  are independently hydrocarbyl groups containing 1 to 30 carbon atoms, provided that at least one of R 1 , R 2  and R 8  contains at least 3 carbon atoms; and a compound of structure (VIII): 
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are independently hydrocarbyl groups containing 1 to 30 carbon atoms, provided that at least one of R 1  and R 2  contains at least 3 carbon atoms. 
     
     
       37. A lubricating oil composition according to  claim 36  wherein the metal-free pre-ceramic polymer is present in the lubricating oil composition in an amount of between 0.001 and 10 percent by weight, based on the weight of the composition. 
     
     
       38. A lubricating oil composition according to  claim 36  wherein the one or more co-additives comprises an antiwear additive, an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant. 
     
     
       39. A lubricating oil composition according to  claim 38  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide from greater than 800 ppm to 1200 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       40. A lubricating oil composition according to  claim 38  wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide no greater than 800 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       41. A lubricating oil composition according to  claim 36  which does not contain a zinc dihydrocarbyl dithiophosphate. 
     
     
       42. A method of lubricating a spark-ignited or compression-ignited internal combustion engine, the method comprising lubricating the engine with a lubricating oil composition according to  claim 36 . 
     
     
       43. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; 
         or wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms, wherein: 1) the one or more co-additives comprises an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant, 2) the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide from greater than 800 ppm to 1200 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185, and 3) said metal-free pre-ceramic polymer having a repeat unit of formula (I): is not capped with an amine or polyamine. 
       
     
     
       44. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; 
         or wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms, wherein: 1) the one or more co-additives comprises an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant, 2) the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide no greater than 800 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185, and 3) said metal-free pre-ceramic polymer having a repeat unit of formula (I): is not capped with an amine or polyamine. 
       
     
     
       45. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer, a zinc dihydrocarbyl dithiophosphate, and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
         
           
           
               
               
           
         
       
       wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms wherein said metal-free pre-ceramic polymer is capped at one or both ends by a capping or chain-terminating group selected from the group consisting of an amine or polyamine. 
     
     
       46. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer is a closed ring structure consisting of a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; and 
         said metal-free pre-ceramic polymer is capped at one or both ends by a capping or chain-terminating group selected from the group consisting of an amide group, an amine or polyamine, an ester, an ether, a thioether and a polymeric residue. 
       
     
     
       47. A lubricating oil composition according to  claim 46  wherein where X is NH or NR. 
     
     
       48. A lubricating oil composition of  claim 46 , wherein said metal-free pre-ceramic polymer is capped at one or both ends by an amide group. 
     
     
       49. A lubricating oil composition of  claim 46 , wherein the number of repeat units of formulae (I) to (IV) in the metal-free pre-ceramic polymer from is from 2 to 5. 
     
     
       50. A lubricating oil composition of  claim 46 , wherein at least one of R, R 1 , R 2 , R 3 , R 5 , R 6  and R 7  contain at least 12 carbon atoms. 
     
     
       51. A lubricating oil composition of  claim 46 , wherein: 1) the one or more co-additives comprises an oil-soluble or oil-dispersible molybdenum-containing compound, a metal-containing detergent, an anti-wear additive, an ashless dispersant, an ashless friction modifier, a viscosity modifier, an anti-oxidant, a rust inhibitor, a copper and lead bearing corrosion inhibitor, a demulsifier or a pour point depressant. 
     
     
       52. A lubricating oil composition of  claim 51 , wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide from greater than 800 ppm to 1200 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       53. A lubricating oil composition of  claim 51 , wherein the one or more co-additives comprises a zinc dihydrocarbyl dithiophosphate in an amount sufficient to provide no greater than 800 ppm by mass of phosphorous to the lubricating oil composition, based upon the total mass of the lubricating oil composition, and as measured in accordance with ASTM D5185. 
     
     
       54. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a metal-free pre-ceramic polymer and one or more co-additives, wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (I): 
       
         
           
           
               
               
           
         
         where X is NH, NR, BR 3  or R 4 ; 
         or wherein the metal-free pre-ceramic polymer contains a repeat unit of formula (II), (III), (IV): 
       
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently linear, branched or cyclic alkyl or alkenyl groups, or aryl groups containing 1 to 30 carbon atoms, where said metal-free pre-ceramic polymer is capped at one or both ends by a capping or chain-terminating group selected from the group consisting of an amide group, an ester, an ether, a thioether and a polymeric residue.